The Boston Celtics successfully got younger this offseason, while still maintaining their veteran roster that brought them to the Eastern Conference finals last year.

The most important move they made was re-signing team leader Kevin Garnett. Garnett sets the attitude for this team and is still effective on both offense and defense, even though he’s now 36 years old. They were also able to sign Jason Terry, a suitable replacement for Ray Allen, away from the Dallas Mavericks.

Besides adding these two veterans, the Celtics also added a number of young players who could be a major factor in the near future. With their two first-round picks, Boston drafted their frontcourt of the future in Jared Sullinger and Fab Melo. These two complement each other very well and will learn a ton playing with Garnett.

Another two young pieces the Celtics will have next season are Jeff Green (25) and Courtney Lee (26). Green, who missed last season after having heart surgery, made a full recovery and will be ready to go next year.

The Nets certainly had the busiest offseason out of any team. Not only did they move from Newark to Brooklyn, but they also needed to re-sign their entire starting lineup from last season.

The Nets had four key starters to re-sign: Deron Williams, Gerald Wallace, Kris Humphries and Brook Lopez. All four were highly sought-after, especially Williams, who was by far the best free agent on the market. The Nets were able to lock all of them up to long-term deals and will now have their lineup set in stone for the next few seasons.

What really turned the Nets into instant contenders this offseason was the trade that brought Joe Johnson to Brooklyn. Johnson still has four years and nearly $90 million remaining on his contract. The Hawks just wanted to dump his large contract, so the Nets were able to grab him for next to nothing in return.

To round out their roster, the Nets also landed reserve players like Tyshawn Taylor, Reggie Evans and Mirza Teletovic, who will play significant roles off the bench.

They also re-signed another starter from last season, Chauncey Billups. Even though Billups was only healthy enough to participate in 20 games last season, he still was a leader in the locker room and great influence for young guards Chris Paul and Eric Bledsoe.

The Clippers also added a few veterans to the roster to really turn this team into true contenders. Jamal Crawford is the former Sixth Man of the Year and will be a great scorer coming off the bench for them.

Grant Hill and Lamar Odom also joined the club. Both veterans can still ball and will be viable scoring options playing on the wing. Hill certainly joined the Clippers in hopes of grabbing a ring before his career comes to a close.

Los Angeles Lakers

Steve Nash (via AP Photo / Reed Saxon)

Key Additions: Antawn Jamison (sign), Steve Nash (trade)

The Lakers didn’t make many moves, but the few they did make were certainly significant.

The Lakers traded for two-time MVP Steve Nash from the Phoenix Suns. Despite Nash’s age (38), he can still be a floor general and lead the Lake Show back to the NBA championship. Nash is an assist master and has finished top-three in assists every season since 2003-2004.

A backcourt of Steve Nash and Kobe Bryant will be one of the best duos in NBA history.

The other key acquisition the Lakers had this offseason was Antawn Jamison. Jamison is a 14-year vet who’s been a dominant scorer his entire career. Unfortunately, he’s never been on a successful team and has only played in 42 postseason games. He’s reached the second round twice, but has never gone further.

That is sure to change next season when the Lakers have a roster filled with six former NBA All-Stars.

Miami Heat

Like the Lakers, the Heat made very few, but very substantial moves this offseason. The Heat won the championship last year and will enter next season with an even better roster than they already had.

The Heat were able to steal Ray Allen away from the Boston Celtics. This move was surprising since Allen will either need to play out of position or come off the bench with Dwyane Wade on the roster as the starting shooting guard.

The Heat were 20th in the NBA in three-pointers made per game last season. Adding the best three-point shooter of all time will surely fix one of the few weaknesses Miami has.

Miami was also able to sign swingman Rashard Lewis to a tiny two-year deal worth only $2.8 million. It’s not often a team can add a player with a career average of 16.1 points per game for such a small amount of money. If Lewis can get back to the form he was once in, the Heat may have gotten the steal of the offseason with this signing.

It’s interesting to note that for many years, Ray Allen and Rashard Lewis were the leaders of the Seattle SuperSonics.

New York Knicks

The Knicks may have lost Jeremy Lin to the Houston Rockets, but they definitely made a ton of moves to make up for his loss.

Lin’s replacement will be Raymond Felton. Felton was the best he’s ever been during his seven-year career as a member of the Knicks. Before getting traded for Carmelo Anthony after 54 games, Felton averaged career highs in points per game (17.1) and assists per game (9.0). More importantly, he helped Amar’e Stoudemire play at an extremely high level during his first season as a member of the Knicks.

In order to bring experience and leadership to their roster, the Knicks went out and signed 18-year veteran Jason Kidd and 16-year veteran Marcus Camby.

Kidd can still be a great distributor and will serve as a mentor for Raymond Felton. Camby is still one of the best defenders and rebounders in the league. He hasn’t lost a step in either of these areas, even though he’s now 38 years old. Having these two players coming off the bench will certainly boost the production of the Knicks’ second unit.

The Knicks were also able to re-sign two other free agents they had on their roster from last season: J.R. Smith and Steve Novak. Both players can light it up from downtown and will be the team’s primary scorers coming off the bench.

Phoenix Suns

You wouldn’t figure the Phoenix Suns could have had a stellar offseason while losing Steve Nash, but they did figure out a way to upgrade the team anyway. This team was in rebuilding mode and brought in a ton of youth that will hopefully grow into title contenders in the near future.

The Suns brought in two point guards to replace Steve Nash. Goran Dragic was a member of the Suns until he was traded to the Houston Rockets two seasons ago. He learned a ton playing behind Steve Nash and will now showcase what he’s learned in his new starting role with Phoenix.

The Suns were also able to draft the best distributing point guard in the draft, Kendall Marshall. As only a sophomore, Marshall led the nation in assists last season with a total of 330. These two point guards will serve as great replacements for the two-time MVP, Steve Nash.

Phoenix also brought in two players who will be their primary scorers moving forward. Michael Beasley has struggled to stay out of trouble off the court thus far in his four-year career, but he has still always managed to score in double figures. Now a member of the Suns, Beasley is confident he will mature and become the All-Star he knows he’s capable of being.

Luis Scola was another great signing the Suns made this offseason. Scola is a gritty basketball player who will become the low-post scorer the Suns have lacked the past few years. Teaming him up with Marcin Gortat should make Phoenix very difficult to rebound against.

Washington Wizards

Any team would consider their offseason tremendously successful if they can add three starters for the following season.

With the third pick in the draft, the Washington Wizards selected Bradley Beal out of the University of Florida. Beal is an extremely dynamic scorer who has unlimited range, as well as the ability to score at the rim. A backcourt of John Wall and Beal will be extremely difficult for opposing teams to defend once they learn how to play together.

In a move to free up cap space, the Hornets traded Emeka Okafor and Trevor Ariza to the Wizards for the disgruntled Rashard Lewis. Okafor is a former Rookie of the Year who will start alongside Nene.

Both men are centers, so the Wizards should have a height advantage and grab and abundance of rebounds when the two are on the floor together. Ariza should also step into a starting role right away. He should be a double-figure scorer since opposing teams need to focus so heavily on the Wizards' backcourt.